MacBook - I just installed a new hard drive in my macbook..

i have a late 07 macbook 2.1, ghz, 4gb ram, and just installed a new 250gb hd because other one went out. i dont have any of the disks or anything as i bought it used and the didnt have it. im thinking about buying leopard install disk from craigslist..is that all i would need? or would there be other disks i need besides the leopard install..? thanks